After enduring years of missile attacks by unmanned aircraft, al-Qaeda is working on ways to disrupt the U.S. drone campaign targeting the terrorist organization.

Drones have taken a heavy toll on al-Qaeda over the past decade, killing thousands and forcing the group’s leaders and operatives to take extreme measures to conceal their movements inside Afghanistan, Pakistan, Somalia, Yemen and other locations.

But since 2010, al-Qaeda has organized cells of engineers to devise methods for jamming, hijacking and even shooting down American drones, according to The Washington Post.

Using classified information released by whistleblower Edward Snowden, the newspaper learned that al-Qaeda technicians are trying to exploit the vulnerabilities of the unmanned planes—specifically the satellite links and remote controls that enable pilots to fly them from thousands of miles away.

A “strategy guide” for how “to anticipate and defeat” drones has been distributed by senior al-Qaeda leaders to its operatives around the globe, one U.S. spy agency learned. And Islamic extremists in North Africa have circulated a tip sheet listing 22 defensive measures to take in the face of an imminent drone attack.

Some of the counter-drone schemes involve shooting down the unmanned aircraft with shoulder-launched missiles, and using jamming devices to interfere with GPS signals and the infrared tags that drone operators utilize to zero in on targets.

Many of the solutions being studied by al-Qaeda are low-tech in nature, such as observation balloons and small radio-controlled aircraft. Others include “lasers and dazzlers” that might blind a drone’s cameras and sensors.

The counter-drone technology is being developed by highly skilled engineers, whom the al-Qaeda leadership hires through extensive recruitment efforts, some of which have been done overtly. A recent issue of an English-language online jihadist magazine, Azan (pdf), published an article about the organization’s anti-drone strategies and issued a call for scientific assistance.

Government officials didn’t seem too alarmed by al-Qaeda’s efforts, per the top-secret report (“Threats to Unmanned Aerial Vehicles”) that summarized dozens of intelligence assessments by U.S. spy agencies since 2006. The study said that the terrorist organization faced “substantial” challenges in overcoming American drones.

The Defense Intelligence Agency (DIA) was quoted in the report as saying in 2011 that an “al-Qaeda-affiliated research and development cell currently lacks the technical knowledge to successfully integrate and deploy counter-drone strike systems.”

However, the DIA assessment did note that if engineers could “overcome these substantial design challenges, we believe such a system probably would be highly disruptive for US operations in Afghanistan and Pakistan.”

The classified documents also revealed U.S. concern over the public relations aspect of drone use, predicting their operations “could be brought under increased scrutiny, perceived to be illegitimate, openly resisted or undermined” via the U.S. courts and media, as well as “citizens with legitimate social agendas.”

Conceding that “drones connote mindless automatons with no capability for independent thought or action … a first attack, which leaves the victim unable to respond,” analysts proposed “elevating the [public] conversation” to the concepts of “preventive military action” and the “inherent right of self-defense.”